RESUMO
PURPOSE: To evaluate oral health-related quality of life (OHRQoL) and satisfaction levels related to treatment in patients who have complete implant treatment and prosthetic rehabilitation after anterior iliac crest grafting. MATERIALS AND METHODS: Fifty-four patients (37 F, 17 M) with a total of 487 implants placed and implant-supported fixed prosthesis treatment completed were included in the study. OHIP-14OHIP-14 scale and satisfaction Likert scale questions were used to evaluate the OHRQoL and the satisfaction levels related to the treatment applied, respectively. To compare the outcomes, the significance test and the Mann-Whitney U-test were used. One-way analyses of variance and Kruskal-Wallis were used to assess the significance of differences among or between the groups. RESULTS: The quality of life (QoL) was higher, and the mean OHIP-14 scores were lower in women, older patients, and cases with a longer follow-up period, recorded as 13.6 ± 10.3 (p: 0.263), 12.9 ± 11.3 (p: 0.079), and 11.8 ± 9.6 (p: 0.015*), respectively. Moreover, satisfaction levels of the patients related to the treatment were 83.3%. CONCLUSIONS: The treatment of severely atrophic jaws with anterior iliac crest for the implant and prosthetic rehabilitation has a positive effect on the QoL. This effect has increased with time, and the satisfaction levels of the patients related to this procedure were high, and their expectations regarding this treatment were met at a high level.
Assuntos
Implantes Dentários , Qualidade de Vida , Humanos , Feminino , Satisfação do Paciente , Ílio/cirurgia , Prótese Dentária Fixada por Implante , Saúde BucalRESUMO
The aim of this study is to evaluate donor- and recipient-site complications of iliac bone grafting for the reconstruction of atrophic jaws.Our study includes 86 consecutive patients with atrophic jaws who underwent iliac bone grafting surgery. At the donor site, hematoma, infection, paresthesia, chronic pain, prolonged gait disturbance, fracture of the ilium, and esthetic concerns; at the recipient site, hematoma, infection, prolonged pain, graft exposure, graft loss, and loss of the implants were evaluated.Grafting was successfully performed in all patients. The mean follow-up period was 35 months. Prolonged gait disturbance (20.9%) and paresthesia (9.3%) were the most frequently observed donor-site complications. At the recipient site, hematoma (8.1%), infection (12.8%), prolonged pain (11.6%), partial graft exposure (33.7%), total graft exposure (7%), partial graft loss (17.4%), and total graft loss (5.8%) were observed.Reconstruction of atrophic jaws can be achieved successfully with iliac bone grafting. However, there are possible donor- and recipient-site complications that have to be taken into consideration.
Assuntos
Transplante Ósseo/efeitos adversos , Ílio/transplante , Doenças Maxilomandibulares/cirurgia , Procedimentos Cirúrgicos Ortognáticos/efeitos adversos , Marcha/fisiologia , Sobrevivência de Enxerto , Hematoma/etiologia , Humanos , Parestesia/etiologia , Complicações Pós-Operatórias/epidemiologiaRESUMO
PURPOSE: This study aimed to evaluate the difference between the stress level and distribution around the BL and TL short implants, and their surrounding structures, using finite element analysis. METHODS: Two different study models were constructed: BL model and TL model. Two dental implant systems (ITI (Straumann, Waldenburg, Switzerland) and NTA Short) with a diameter of 4.1 mm and 4 mm and with a length of 6 mm were used in this study. In each model, implants were placed in the mandibular 1st molar region. The von Mises stress and maximum principal (tensile) and minimum principal (compressive) stresses were evaluated. RESULTS: The highest stress values recorded in the BL implants (von Mises: 342.77 MPa), in the periimplant bone around the BL implants (maximum principal stress: 114.1 MPa), as a result of oblique loading, and overall stress values were found to be higher in the BL model. However, these measured values appeared to be low to cause a fracture, when considering the yield strengths of the materials and bone. CONCLUSIONS: The stress values were higher in the BL model, but not high enough to cause failure. Short implants could be an effective method of treatment for patients unsuitable for advanced surgical techniques.
Assuntos
Implantes Dentários , Humanos , Análise de Elementos Finitos , SuíçaRESUMO
INTRODUCTION AND OBJECTIVES: Trichorhinophalangeal syndrome (TRPS) is a rare multisystem disorder characterized by abnormalities in the hair (tricho), nose (rhino), and digits (phalangeal). A variety of nonspecific intraoral findings have been reported in the literature, including hypodontia, delayed tooth eruption, malocclusion, a high-arched palate, mandibular retrognathia, midface hypoplasia, and multiple impacted teeth. In addition, supernumerary teeth have been detected in several persons with TRPS, especially type 1. This report describes the clinical manifestations and dental management of a TRPS 1 patient with multiple impacted supernumerary and permanent teeth. PATIENT: A 15-year-old female patient visited our clinic with a known medical history of TRPS 1 with laceration of the tongue caused by teeth eruption in the palate. RESULTS: Radiographic images showed a total of 45 teeth: two deciduous, 32 permanent, and 11 supernumerary teeth. Six permanent teeth and 11 supernumerary teeth in the posterior quadrants were impacted. Four impacted third molars, supernumerary teeth, retained deciduous teeth, and impacted maxillary premolars were removed under general anaesthesia. DISCUSSION AND CONCLUSIONS: This case suggests that all patients with TRPS should undergo full clinical and radiographic oral examination and should be informed about the disease and the importance of dental counselling.
Assuntos
Doenças do Cabelo , Síndrome de Langer-Giedion , Dente Impactado , Dente Supranumerário , Feminino , Humanos , Adolescente , Síndrome de Langer-Giedion/diagnóstico , NarizRESUMO
BACKGROUND: There are several challenges in terms of mandibular reconstruction. The defect size, graft materials, and plate combinations should be taken into consideration in surgical planning. OBJECTIVE: The aim of this study was to evaluate the effect of different reconstruction variations on the stress distribution of segmental resected mandibles with two different defect sizes using finite element analysis (FEA). METHODS: Computerized tomography images of a human mandible, fibula, and iliac crest were used as references to build three-dimensional (3D) models on a PC. The virtual plates and screws were used to simulate reconstruction of the mandibular defects. The models were divided into two groups based on the longitudinal defect size. Different osteosynthesis variations and autogenous graft material combinations were used to reconstruct the mandibles. RESULTS: In all models, higher von Mises stress values occurred on the mandibles reconstructed with the fibula than those with the iliac crest. Fixation of the bone grafts with a reconstruction plate for the 10-mm defects and using a mini-plate in addition to the reconstruction plate for the 30-mm defects decreased stresses on the grafted bones. CONCLUSIONS: Mandibular reconstruction with the iliac grafts is biomechanically superior to that with the fibular grafts. In addition, osteosynthesis methods and the defect size affect the stress distribution.
Assuntos
Transplante Ósseo/métodos , Reconstrução Mandibular/métodos , Modelos Anatômicos , Realidade Virtual , Placas Ósseas , Fíbula/anatomia & histologia , Análise de Elementos Finitos , Humanos , Ílio/anatomia & histologia , Mandíbula/anatomia & histologia , Estresse Mecânico , Tomografia Computadorizada por Raios XRESUMO
OBJECTIVE: To compare the primary stability of implants placed in conventional and osteotome sites and to evaluate the level of correlation between cutting torque measurements, resonance frequency analysis (RFA), and bone density. MATERIALS AND METHODS: Eight human femoral heads were scanned with computed tomography for bone density measurements as Hounsfield units (HU), and individualized computed tomography-based surgical stents were prepared for placement of implants. Five implant sockets were prepared in each collum (CoF), caput (CaF), and trochanter (Tr-MM) section of the femoral heads using the conventional drilling technique or by a combination of drilling and use of an osteotome. Cutting-torque values (CTV) of the implants were measured by a manual torque wrench, followed by determination of implant stability quotients (ISQ) by RFA. RESULTS: The CTVs of implants were similar in the conventional group, but different in the osteotome group (P<0.05). There was a general tendency toward achieving higher CTV and ISQ values in CoF than CaF and Tr-MM (P<0.05), and measurements in CaF and Tr-MM were comparable (P>0.05). The mean HU of sites were similar, although CoF had higher HU values (P>0.05). CTV of implants in CaF and Tr-MM and ISQ values in CoF in the conventional groups were higher than those in the osteotome groups (P<0.05). The correlation between CTV and HU in Tr-MM was significant in the osteotome group, although no other correlations between CTV, ISQ, and HU could be detected (P>0.025). CONCLUSIONS: Conventional placement led to higher implant stability than the drilling and osteotome technique used in the study. No correlation could be found between CTV, RFA, and bone density.
Assuntos
Densidade Óssea , Implantação Dentária Endóssea/métodos , Implantes Dentários , Retenção em Prótese Dentária , Fêmur/cirurgia , Idoso , Implantação Dentária Endóssea/instrumentação , Falha de Restauração Dentária , Análise do Estresse Dentário/instrumentação , Análise do Estresse Dentário/métodos , Fêmur/anatomia & histologia , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Osteotomia/instrumentação , Estatísticas não Paramétricas , Tomografia Computadorizada por Raios X , Torque , VibraçãoRESUMO
PURPOSE: As formalin is an extremely reactive electrophilic chemical that reacts with tissues, the purpose of this study was to explore whether formalin fixation could potentially alter the mechanical properties of bone tissue and have an effect on the primary stability measurements of implants. MATERIAL AND METHODS: Ø 3.3 x 8 mm, Ø 4.1 x 8 mm, and Ø 4.8 x 8 mm implants were placed on sockets prepared into the anterior surface of the radius of two fresh-frozen human cadavers. The insertion torque of each implant was quantified using a strain-gauged torque-wrench connected to a data acquisition system at a sample rate of 10 KHz, and resonance frequency analysis measurements were also undertaken for each implant. The cadavers were then subjected to embalment with 10% formalin for 3 months, and the same experiments were undertaken on the contra lateral radius of the cadavers. RESULTS: The insertion torques before and after chemical fixation were similar for Ø 3.3 mm (P>0.05), and higher values were obtained for Ø 4.1 mm and Ø 4.8 mm implants after chemical fixation (P<0.05). The resonance frequency analysis values before and after chemical fixation were similar for all implants (P>0.05). CONCLUSIONS: Implants have higher insertion torque values in formalin-fixed bone than fresh-frozen human bone, but similar implant stability quotients in both cases. The insertion torque technique can detect the difference between formalin-fixed and fresh-frozen human bone, but resonance frequency analysis cannot.
Assuntos
Fenômenos Biomecânicos/efeitos dos fármacos , Análise do Estresse Dentário/métodos , Fixadores/farmacologia , Formaldeído/farmacologia , Rádio (Anatomia)/efeitos dos fármacos , Implantação Dentária Endóssea/métodos , Implantes Dentários , Humanos , Masculino , Modelos Anatômicos , Preservação de Tecido/métodos , TorqueRESUMO
PURPOSE: The purpose of this study was to qualify and quantify bone strains around immediately-loaded implants supporting mandibular fixed prostheses with regard to number of implant support. MATERIALS: Linear strain gauges were bonded on the labial bone of 5 Straumann dental implants placed in the mandibular symphysis region of 2 completely edentulous mandibles of fresh human cadavers. Installation torque value of each implant was measured by a custom-made torque wrench and resonance frequency analyses were undertaken. A one-piece full-arch fixed prosthesis was fabricated for each cadaver and 2 miniature load cells were integrated in the cantilever region of the prostheses for controlled loading experiments. 5-, 4-, and 3-implant support designs were consecutively tested. Strain measurements were performed at a sample rate of 10 KHz and under a maximum load of 100 N, simultaneously monitored from a computer connected to data acquisition system. RESULTS: The installation torque values and implant stability quotient values of the implants ranged between 42.12 to 145.67 N cm and 61 to 80, respectively. Between-group comparisons revealed that the highest strain magnitudes were recorded for the 3-implant design followed by the 4- and 5-implant designs, although there was a tendency toward similar load partitioning between 4- and 5-implant designs (P < 0.05). CONCLUSIONS: Bone strains around 3-implant supported mandibular fixed prostheses is significantly higher than those around 4- and 5-implant designs, and this may lead to failure of supporting implants. Four- and 5-implant designs might have similar clinical outcome.
Assuntos
Processo Alveolar/fisiologia , Prótese Dentária Fixada por Implante , Análise do Estresse Dentário , Prótese Total Imediata , Idoso , Cadáver , Implantação Dentária Endóssea , Retenção em Prótese Dentária , Análise do Estresse Dentário/instrumentação , Análise do Estresse Dentário/métodos , Prótese Total Inferior , Humanos , Arcada Edêntula/fisiopatologia , Arcada Edêntula/reabilitação , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , TorqueRESUMO
Inversion of premolars is an extremely rare condition, which usually requires extraction. This case report describes the inversion of an impacted maxillary second premolar in an 11-year-old male, and the multidisciplinary treatment approach for bringing the tooth into a normal position within the arch. In order to provide sufficient space for surgical reimplantation of the tooth, the mesially-drifted neighbouring maxillary first molar was first endodontically treated, followed by orthodontic distalization of the tooth. The inverted tooth was removed surgically and reimplanted without the use of splints for stabilization. After a 12-month follow-up period, the tooth maintained its vitality without any root resorption. Reimplantation of impacted inverted premolars can be a viable treatment alternative to extraction.
Assuntos
Dente Pré-Molar/lesões , Reimplante Dentário , Criança , Humanos , Masculino , Maxila , Equipe de Assistência ao Paciente , Técnicas de Movimentação Dentária , Dente Impactado/cirurgiaRESUMO
OBJECTIVE: The aim of this study was to compare the peri-implant bone level changes of implants placed during and 3 months after bone grafting from the iliac crest. STUDY DESIGN: A total of 103 implants were placed: 42 during the grafting and 61 at 3 months after the grafting procedure. All patients were grafted with iliac bone from the anterosuperior iliac crest. Bone resorption was evaluated with cone beam computed tomography in all patients at their last control visit. Periodontal health was assessed via the gingival and plaque indices and pocket depths around the dental implants. RESULTS: Mean bone resorption values at the buccal, lingual, mesial, and distal sides of the implants were 1.08 mm, 0.36 mm, 0.30 mm, and 0.25 mm, respectively, in the delayed group, and 1.87 mm, 1.25 mm, 0.92 mm, and 1.23 mm, respectively, in the simultaneous group; the differences between the groups were significant. There were no significant between-group differences in the gingival or plaque indices or pocket depths. The mean follow-up period was 29 months. CONCLUSIONS: For reconstructing atrophic jaws, bone grafting from the iliac crest and implant placement after 3 months is a reliable technique with a high success rate and less bone resorption.
Assuntos
Aumento do Rebordo Alveolar/métodos , Reabsorção Óssea/diagnóstico por imagem , Tomografia Computadorizada de Feixe Cônico , Implantação Dentária Endóssea/métodos , Implantes Dentários , Ílio/transplante , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índice Periodontal , Resultado do TratamentoRESUMO
PURPOSE: To compare the biomechanical effect of splinted versus unsplinted mandibular implants supporting overdentures subjected to experimental static immediate load on bone tissue deformation using strain gauge analysis. MATERIALS AND METHODS: Strain gauges were bonded on the labial cortical bone adjacent to 2 Straumann dental implants placed in the mandibular interforaminal region of 4 completely edentulous mandibles of fresh human cadavers. The installation torque value (ITV) of each implant was measured using a custom-made torque wrench, and implant stability quotients (ISQs) were also obtained using resonance frequency analysis. Three overdentures (ODs), 2 splinted (bar- and cantilevered bar-retained) and 1 unsplinted (ball-retained), were fabricated for each edentulous mandible. Two experimental loads were applied subsequently via 2 miniature load cells that were placed bilaterally 10 mm (anterior loading) and 15 mm (posterior loading) from the implant. Strain measurements were performed at a sample rate of 10 KHz and under a maximum experimental static load of 100 N; they were simultaneously monitored from a computer connected to a data acquisition system. Finally, the removal torque values (RTV) of the implants were measured. RESULTS: Strains on the labial cortical bone around implants supporting mandibular ODs under anterior loading were significantly higher than measured under posterior loading for all attachment types (P < .05). All strain values were compressive in nature, and the minimum strain (-19 microepsilon) was recorded for bar-retained ODs under 25 N posterior loading, while the maximum strain (-797 microepsilon) was for recorded for retentive anchor-retained ODs under 100 N anterior loading. Nonparametric correlations between ISQs, ITVs, and RTVs identified significant correlations only for ITVs and RTVs (P < .05). CONCLUSION: Splinting of 2 interforaminal dental implants, regardless of attachment type, to support mandibular ODs subjected to immediate load significantly reduced initial bone tissue strains experienced on the labial cortical bone in comparison with the use of unsplinted implants.
Assuntos
Implantes Dentários , Prótese Dentária Fixada por Implante , Planejamento de Dentadura , Revestimento de Dentadura , Mandíbula/fisiopatologia , Processo Alveolar/fisiopatologia , Cadáver , Dente Suporte , Implantação Dentária Endóssea , Retenção de Dentadura , Humanos , Arcada Edêntula/fisiopatologia , Arcada Edêntula/cirurgia , Mandíbula/cirurgia , Processamento de Sinais Assistido por Computador , Estresse Mecânico , Torque , TransdutoresRESUMO
The objective of this study was to compare the bone strains of apically free versus grafted implants in the posterior maxilla. The experiments were undertaken in four edentulous maxillary posterior regions of fresh human cadavers, having a minimum bone height of 8 mm. In each bone fragment, two Ø 4.1 mm x 12 mm Straumann implants were placed, and insertion torque values (ITV) and implant stability quotients (ISQ) of the implants were quantified to determine implant anchorage. Two splinted crowns were fabricated for each experimental model. Strain gauges were bonded on the buccal and sinus floor cortical bones around apically free and grafted implants. Microstrains were recorded by a data acquisition system and corresponding software at a sample rate of 10 KHz under central and buccally oriented lateral-axial static loads of 100 and 150 N in separate cases. The data were compared by independent T test at a significance level set at P<0.05. Bone tissue strains on the buccal cortical areas adjacent to apically free implants were higher than those of apically grafted implants (P<0.05). The differences ranged between 10 and 48 mu epsilon under central and lateral axial loads of 100 and 150 N. The shift in load application from central to buccally oriented lateral axial mode increased strains between 60 and 201 mu epsilon on buccal cortical bone around apically free and grafted implants (P<0.05). Bone strains around anterior implants were higher than those of posterior implants. Microstrains in the sinus floor cortical bone in apically grafted models were slightly higher than apically free models. Bone tissue strains on the buccal cortical areas adjacent to apicallyfree implants are higher than those of apically grafted implants. Sinus lifting, resulting in an enhanced apical support, slightly increases strains at the sinus floor region, but leads to a decrease in bone strains around the collar of supporting implants.
Assuntos
Implantes Dentários , Arcada Parcialmente Edêntula/fisiopatologia , Maxila/fisiologia , Fenômenos Biomecânicos , Cadáver , Planejamento de Prótese Dentária , Prótese Dentária Fixada por Implante , Análise do Estresse Dentário/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Estresse MecânicoRESUMO
The purpose of this study was to quantify strains in coagulum around immediately loaded oral implants in extraction sockets at the ex vivo level. Bilateral maxillary premolar teeth of two fresh human cadavers were extracted and psi 4.1 x 12 mm Straumann TE implants were placed in the sockets of first and second premolars by utilizing mesio-distal and palatal anchorage, respectively. Installation torque value (ITV) of each implant was measured by a custom-made torque wrench and resonance frequency analyses (RFAs) were undertaken to determine intraosseous stability. Upon abutment connection, a gold coping allowing the placement of a miniature load cell to contact the underlying solid abutment was fabricated. A linear strain gauge was connected to the coping at a distance for strain measurements in coagulum around the implant neck in the extraction socket. Linear strain gauges were also bonded on the labial marginal bone of each extraction socket. Strain measurements were performed at a sample rate of 10 kHz simultaneously monitored from a computer connected to data acquisition system and under a maximum load of 100 N on each implant with or without human coagulum in the extraction socket. Low-amplitude strains were measured around immediate implants. The increase in load increased strains on labial marginal cortical bone around implants (P < 0.05). Bone strains were higher on the implant loaded, when coagulum was present in the bone defects (P < 0.05). Strains within coagulum around mesiodistally anchored implants were higher than palatally anchored implants (P < 0.05). The type of implant on anchorage and presence of coagulum has an impact mechanotransduction to buccal marginal bone around immediate implants.
Assuntos
Implantação Dentária Endóssea , Implantes Dentários para Um Único Dente , Análise do Estresse Dentário , Alvéolo Dental/fisiopatologia , Coagulação Sanguínea , Humanos , Modelos Biológicos , Estresse Mecânico , Extração DentáriaRESUMO
The purpose of this retrospective study was to assess the results after a follow-up of 10 years of autotransplantation of canines and third molars without the use of any apparatus for stabilisation. A total of 96 teeth were transplanted and 83 were successful (86%). The technique is easy, reliable, and effective.
Assuntos
Dente Canino/transplante , Dente Serotino/transplante , Procedimentos Cirúrgicos Bucais/métodos , Adolescente , Adulto , Feminino , Humanos , Masculino , Contenções Periodontais , Estudos Retrospectivos , Dente Impactado/cirurgia , Resultado do TratamentoRESUMO
PURPOSE: To compare the primary stability of dental implants placed in fibula, iliac crest, and scapula of human cadavers. MATERIALS AND METHODS: Straumann Dental Implants (Institut Straumann, Basel, Switzerland) 4.1 mmx10 mm in diameter were placed into bilateral fibula, iliac crest, and scapula of 4 fresh human cadavers. For the assessment of primary stability of implants, installation torque values (ITV) and removal torque values (RTV) were measured using a custom-made strain-gauged torque wrench, and resonance frequency analysis was carried out to quantify the implant stability quotients (ISQ). Bone specimens from each donor site were harvested to perform radiographic and histomorphometric analyses. Linear distance and optical density (OD) measurements were made on digitized parallel periapical radiographs and bone area fraction (BAF) was calculated on digitized images of decalcified histologic sections. RESULTS: Fibula donor site presented higher ITVs and RTVs and cortical bone height for implants than other sites (P<.05). BAF measurements for iliac crest were higher than fibula and scapula bone donor sites. OD was higher in the iliac crest followed by scapula and fibula. CONCLUSION: The primary mechanical stability of implants placed in the fibula is higher than those placed in the iliac crest and the scapula, although the bone mass and density around implants in latter sites are higher.
Assuntos
Transplante Ósseo/fisiologia , Implantação Dentária Endóssea/métodos , Retenção em Prótese Dentária , Fíbula/fisiologia , Ílio/fisiologia , Escápula/fisiologia , Idoso , Densidade Óssea , Cadáver , Análise do Estresse Dentário , Feminino , Fíbula/cirurgia , Humanos , Ílio/cirurgia , Implantes Experimentais , Masculino , Pessoa de Meia-Idade , Osseointegração , Escápula/cirurgia , Estatísticas não Paramétricas , Torque , VibraçãoRESUMO
BACKGROUND: Owing to the complexity and magnitude of functional forces transferred to the bone-implant interface, the mechanical strength of the interface is of great importance. The purpose of this study was to determine the intraosseous torsional shear strength of an osseointegrated oral implant using 3-D finite element (FE) stress analysis implemented by in vivo failure torque data of an implant. METHODS: A Ø 3.5 mm x 12 mm ITI hollow screw dental implant in a patient was subjected to torque failure test using a custom-made strain-gauged manual torque wrench connected to a data acquisition system. The 3-D FE model of the implant and peri-implant circumstances was constructed. The in vivo strain data was converted to torque units (N x cm) to involve in loading definition of FE analysis. Upon processing of the FE analysis, the shear stress of peri-implant bone was evaluated to assume torsional shear stress strength of the bone-implant interface. RESULTS: The in vivo torque failure test yielded 5952 microstrains at custom-made manual torque wrench level and conversion of the strain data resulted in 750 N.cm. FE revealed that highest shear stress value in the trabecular bone, 121 MPa, was located at the first intimate contact with implant. Trabecular bone in contact with external surface of hollow implant body participated shear stress distribution, but not the bone resting inside of the hollow. CONCLUSION: The torsional strength of hollow-screw implants is basically provided by the marginal bone and the hollow part has negligible effect on interfacial shear strength.
Assuntos
Parafusos Ósseos , Implantes Dentários , Prótese Dentária Fixada por Implante , Análise do Estresse Dentário/métodos , Modelos Dentários , Análise de Elementos Finitos , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Falha de PróteseRESUMO
PURPOSE: To compare ex vivo bone tissue strains around natural teeth with immediate implants supporting unsplinted and splinted fixed prostheses. MATERIAL AND METHODS: Six linear strain gauges were bonded on the labial marginal bone of bilateral maxillary anterior teeth in two fresh-frozen human cadavers. The natural teeth were loaded in centric occlusion via an occlusal splint with integrated miniature load cells. Strain measurements were performed at a sample rate of 10 kHz and under a maximum load of 100 N, simultaneously monitored from a computer connected to data acquisition system. Upon extraction of the anterior teeth, Ø 4.1 mm and Ø 4.8 mm ITI dental implants were placed into sockets of incisors and canines, respectively. Installation torque value (ITV) of each implant was measured by a custom-made torque wrench and resonance frequency analyses (RFA) were also undertaken. Strain measurements were performed for (1) single-tooth implant restorations, (2) unilateral splinted anterior implants, and (3) bilateral splinted anterior implants. Finally, an autopolymerizing acrylic resin was injected into the implant sockets for simulation of osseointegration and strain measurements were performed. RESULTS: Microstrains of all groups were statistically comparable (P>0.05), although lower strains were elicited for implants in sockets of incisors in comparison with natural teeth. Microstrains around canine implants were comparable or higher than those induced around natural canines. For all groups, microstrains around canines were higher than those around lateral (P<0.05) and central incisors (P<0.01), which had similar strain levels (P>0.05). The RFA values of implants were comparable. The ITVs of implants in sockets of lateral incisors and canines were similar and were higher than those of implants in central incisor regions. CONCLUSION: The labial marginal bone having no contact with immediate implants may experience strain gradients within physiologic levels due to deformation of bone under load. Although one prosthetic design does not seem to have clear advantages over another, splinting of implants may be considered as a safety measure for immediately loaded immediate implants, if possible.
Assuntos
Osso e Ossos/fisiologia , Implantes Dentários , Adulto , Osso e Ossos/química , Cadáver , Humanos , Masculino , Pessoa de Meia-Idade , Placas Oclusais , Estatísticas não Paramétricas , Fatores de Tempo , Suporte de CargaRESUMO
PURPOSE: To evaluate ex vivo bone tissue strains around maxillary implants supporting immediately loaded bar-retained overdentures. MATERIAL AND METHODS: Ninety degree two-element rosette strain gauges were bonded on the labial bone of four ITI dental implants placed in the maxillary anterior region of four completely edentulous maxilla of fresh human cadavers. The installation torque value (ITV) of each implant was measured by a custom-made torque wrench and resonance frequency analyses (RFAs) were undertaken. A bar-retained overdenture was fabricated for each cadaver, and two miniature load cells were integrated in the first molar region of the overdentures for controlled loading experiments. Strain measurements were performed at a sample rate of 10 kHz and under a maximum load of 100 N, simultaneously monitored from a computer connected to a data acquisition system. Finally, removal torque values (RTVs) of the implants were measured. RESULTS: RFA values did not mirror ITVs, while RTVs of implants were slightly lower than the ITVs. Any correlation could not be obtained between RFA values and ITVs or RTVs. Maximum strains around loaded implants ranged between -100 and -550 microepsilon under 25-100 N. The axial and lateral strain values of posterior implants of both sides were higher than those of anterior implants under all loads (P<0.05). CONCLUSION: Because occlusal forces in humans tend to decrease because of age-related factors, maximum strains around immediately loaded implants supporting maxillary overdentures fall within physiologic levels.
Assuntos
Implantes Dentários , Prótese Dentária Fixada por Implante/efeitos adversos , Análise do Estresse Dentário , Maxila/fisiologia , Idoso , Força de Mordida , Cadáver , Análise do Estresse Dentário/estatística & dados numéricos , Retenção de Dentadura/instrumentação , Revestimento de Dentadura , Prótese Parcial Imediata , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estatísticas não Paramétricas , Estresse Mecânico , Torque , VibraçãoRESUMO
OBJECTIVE: The objective of this study was to explore effects of implant macrodesign and diameter on initial intraosseous stability and interface mechanical properties of immediately placed implants. MATERIAL AND METHOD: Mandibular premolars of four fresh-frozen human cadavers were extracted. Ø 4.1/4.8 mm ITI TE, Ø 4.1 and 4.8 mm solid screw synOcta ITI implants were placed into freshly prepared extraction sockets. Resonance frequency analysis was conducted to quantify primary implant stability quotient (ISQ). Installation torque value (ITV) and removal torque value (RTV) of the implants were measured using a custom-made strain-gauged torque wrench connected to a data acquisition system at a sample rate of 10,000 Hz. The vertical defect depth around the collar of each implant was measured directly by an endodontic spreader. The bone-implant contact was determined in digitalized images of periapical radiographs and expressed as percentage bone contact. RESULTS: The ISQ values of the TE implant was higher than the Ø 4.1 mm implant (P<0.01), and comparable with the Ø 4.8 mm implants (P>0.05). ITVs and RTVs of TE and Ø 4.8 mm implants were higher than the Ø 4.1 mm implant, although the differences between groups were statistically insignificant (P>0.05). The vertical defect depths around all types of implants were similar. In the radiographic analyses, percentage bone-implant contact of the TE and Ø 4.8 mm implants were comparable at the marginal bone region and both were higher than that of the Ø 4.1 mm ITI implant. Nonparametric correlations between groups revealed a significant correlation between ITV and RTV (r=0.838; P<0.001), but not between ISQ values and ITVs and RTVs (P>0.05). CONCLUSION: Immediately placed ITI TE implant leads to initial intraosseous stability and interface mechanical properties comparable with a wide diameter implant.
Assuntos
Implantação Dentária Endóssea/normas , Implantes Dentários/normas , Planejamento de Prótese Dentária , Adulto , Idoso , Cadáver , Implantação Dentária Endóssea/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estatísticas não Paramétricas , Fatores de Tempo , TorqueRESUMO
PURPOSE: Sialoliths are common in the submandibular gland and its duct system. The exact cause of formation of a sialolith is still a matter of debate. The aim of this study was to analyze 6 sialoliths ultrastructurally to determine their development mechanism in the submandibular salivary glands. MATERIALS AND METHODS: Six sialoliths retrieved from the hilus and duct of the submandibular salivary glands of 6 patients with sialadenitis were analyzed ultrastructurally by scanning electron microscope and x-ray diffractometer. RESULTS: Scanning electron microscope revealed mainly irregular, partly rudely hexagonal, needle-like and plate-shaped crystals. The cross-section from the surface to the inner part of the sialoliths showed no organic material. X-ray diffraction showed that the sialoliths were composed of hydroxyapatite crystals. Energy dispersive x-ray microanalysis showed that all of the samples contained high levels of Ca and P, and small amounts of Mg, Na, Cl, Si, Fe, and K. CONCLUSION: The main structures of the submandibular sialoliths were found to be hydroxyapatite crystals. No organic cores were observed in the central parts of the sialoliths. In accordance with these preliminary results, sialoliths in the submandibular salivary glands may arise secondary to sialadenitis, but not via a luminal organic nidus.